Urban Heating in China's Shenzhen Economic Zone

Reference
Tian, L., Chen, J. and Yu, S. 2013. How has Shenzhen been heated up during the rapid urban build-up process? Landscape and Urban Planning115: 18-29.

According to Tian et al. (2013), the "air temperature of an urban area is among the most important environmental variables for human beings," while noting that Oke (1973) had suggested fully four decades ago that "regional urbanization and industrialization [had been] more influential on the regional temperature than global warming," additionally citing Chung et al. (2004) in this regard. Against this backdrop Tian et al. used long-term climatic records of 1961-2010 in the Shenzhen Economic Zone (SEZ) - which they downloaded from the China Meteorological Data Sharing Service System - to assess potential urbanization-induced heating increases.

The three researchers report that "on a global scale," according to the Intergovernmental Panel on Climate Change, the daily mean temperature "has increased by 0.13°C/decade over the last 12 years (1995-2006)," while they found that the similarly-defined warming ratio over the last 25 years was a much larger 0.45°C/decade for the SEZ, which finding they say "is consistent with other reports for the SEZ," citing Si et al. (2010) and Xie et al. (2011). In addition, they found that the daily minimum temperature appeared to be the most sensitive variable quantifying the magnitude and direction of the Urban Heat Island, and that it had increased by 2.33°C in the winter and 1.24°C in the summer over the course of their study, "in agreement with other results in the subtropics (Bai et al., 2011; Hsu and Chen, 2002; Jonsson, 2004; Zhang et al., 2010; Zhong, 1996) and in the tropics (Jauregui, 1997)."

Tian et al.'s findings that urbanization-induced warming was "more pronounced for minimal temperatures and in the wintertime" bodes well for human health, in light of the fact that real-world colder temperatures - on both a daily and seasonal basis - lead to far greater human mortality than do real-world warmer temperatures.